Effects of Aerobic Pre-Treatment on Anaerobic Batch Digestion of Corn Straw

Applying an aerobic pre-treatment (AP) to corn straw prior to anaerobic digestion (AD) could ameliorate the limits of hydrolysis and enhance the efficiency of biogas production. The results of this study indicated that the accumulation of acetate in the total volatile fatty acids (VFAs) fraction was highest using the AP process, which accounted for more than 60% of total VFAs and potentially benefited methane production. Compared with that of the original untreated straw, the degradation rates of lignin, cellulose and hemicellulose for straw that had undergone a 24 h AP were increased by 8.02, 25.73 and 28.80%, respectively. The first order and modified Gompertz kinetic models both showed that the lag time of the methanogenic stage was shorter than that of the control group. In the group that received the AP for 16 h (APG-16 h), the maximum methane yield was 237.29 mL/g volatile solid (VS), which was 21.33% higher than that of the control group. A short AP period was demonstrated to be beneficial for the AD of corn straw and could represent an effective option for promoting methane production.